JPH06138744A - Color image forming device - Google Patents

Abstract

PURPOSE:To provide a color image forming device which facilitates maintenance and the removal of a jammed sheet, is highly reliable, compact and a simple structure. CONSTITUTION:The color image forming device is provided with a belt-like image carrier (1), a latent image forming means (30), a multicolor development unit (100), and a belt-like intermediate transfer body (201). The belt-like intermediate transfer body (201) is supported so as to have at least two flat surfaces, and has a transfer means (204) near one end of the upper flat surface. The belt-like image carrier (l) is supported so as to have at least two flat surfaces, and has the multicolor development unit (100) on the vertical flat surface, intermediate transfer means (202a and 202b) at the top of the vertical flat surface, and a destaticizing device (6) and an electrifying device (2) on the lower flat surface opposite to the vertical flat surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in color printers, color facsimiles, color copying machines, etc., and has one intermediate transfer belt and one photoconductor belt, and a plurality of photoconductor belts are provided around the photoconductor belt. Electrophotographic color image forming apparatus in which the developing device of FIG.

[0002]

2. Description of the Related Art Conventionally, various proposals have been made regarding the structure of an electrophotographic color image forming apparatus having one intermediate transfer belt and one photosensitive belt. For example, in Japanese Unexamined Patent Publication No. 62-182766, the peripheral length ratio of the photoconductor belt and the intermediate transfer belt is set to 2: 1 and a plurality of developing devices are installed on the upper surface of the photoconductor belt which is arranged horizontally. There is disclosed a color image forming apparatus in which a transfer belt is disposed substantially orthogonal to one end surface of a photoconductor belt, and a transfer paper conveyance path is located below the intermediate transfer belt and the photoconductor belt. Further, in Japanese Patent Application Laid-Open No. 4-5669, a photosensitive belt is placed vertically and a multicolor developing device is provided on one side thereof, and a black and white developing device, a decharger, a cleaner and a writing section are provided on the other side thereof, and an intermediate transfer is provided at the bottom. A color image forming apparatus is disclosed in which belts are arranged orthogonally to each other, and a transporting path for a transfer paper is placed below an intermediate transfer belt. Further, in JP-A-63-292156, the peripheral length ratio of the photoconductor belt and the intermediate transfer belt is set to 2: 1 and a plurality of developing devices are installed on the upper surface of the photoconductor belt which is obliquely arranged.
There is disclosed a color image forming apparatus in which an intermediate transfer belt is arranged at the lowermost end surface portion of a photoreceptor belt, and a transfer paper conveyance path is located below the intermediate transfer belt. Further, in Japanese Patent Laid-Open No. 3-249671, the circumference ratio of the photoconductor belt and the intermediate transfer belt is set to 1: 1 and the photoconductor belt is arranged vertically, and a plurality of developing devices are installed on one side surface of the photoconductor belt. Then
There is disclosed a color image forming apparatus in which an intermediate transfer belt is obliquely arranged on the uppermost end surface portion of a photoconductor belt, and a transfer paper conveyance path is located below the intermediate transfer belt. further,
In U.S. Pat. No. 4,956,676, a photosensitive belt is vertically arranged, a plurality of developing devices are installed on one side surface thereof, an intermediate transfer belt is horizontally arranged at an uppermost end surface portion of the photosensitive belt, and a transfer paper is conveyed. A color image forming apparatus is disclosed in which a passage is placed above an intermediate transfer belt (which also serves as a conveyor belt).

[0003]

However, in the above-mentioned conventional color image forming apparatus, the size of the entire apparatus tends to increase as the apparatus configuration becomes complicated.
At the time of maintenance, there has been a problem that operability is deteriorated, such as developer and toner being scattered to cause color mixing, and replacement of the photoconductor and the intermediate transfer belt is not easy. Further, there is a problem that the transferability of the transfer paper and the operability at the time of paper jam (jam) are deteriorated. Therefore, an object of the present invention is to provide a color image forming apparatus that solves the above-mentioned conventional problems, is easy to perform maintenance and paper jam handling, has high reliability, and is more compact and simple in configuration. There is.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is to provide one belt-shaped image carrier and latent image formation for forming an electrostatic latent image corresponding to an image of each color on the belt-shaped image carrier. Means, a multicolor developing unit which is arranged around the belt-shaped image bearing member and applies a plurality of colors of developers to the belt-shaped image bearing member, and the electrostatic image formed on the belt-shaped image bearing member. In a color image forming apparatus including one belt-shaped intermediate transfer member to hold the belt-shaped intermediate transfer member, the belt-shaped intermediate transfer member is supported so as to have at least two flat surfaces, including one substantially horizontal flat surface. A transfer means for transferring the toner image onto the transfer paper is provided near one end of the flat surface, and the belt-shaped image carrier has at least two flat surfaces including one vertical flat surface. Supported, multicolor development on this vertical flat surface A knit, an intermediate transfer means for transferring a toner image to the belt-shaped intermediate transfer member on the top of the vertical flat surface, and a static eliminator and a charger on the lower flat surface facing the vertical flat surface. Further, an upper opening / closing lid for exposing the transfer means and the conveying means to perform processing when a paper jam occurs is provided on the upper part of the apparatus main body, and the belt-shaped image carrier and the belt-shaped image carrier on the side surface of the apparatus main body. There is a side opening / closing lid for making the intermediate transfer member detachable.

[0005]

Therefore, since the transfer means is provided in the vicinity of one end of the belt-shaped intermediate transfer member, the transfer distance of the transfer paper is shortened. Since the multicolor developing unit is provided on the lower surface side of the belt-shaped image carrier and the latent image forming means is provided below the multicolor developing unit (or the rotary multicolor developing unit), Space is effectively used, resulting in a more compact structure. Further, when the rotary multicolor developing unit is used, the developing space is simplified, so that the belt-shaped image carrier can be made compact. Further, by opening the upper opening / closing lid on the upper surface of the apparatus main body, the transfer means and the conveying means are exposed, and the processing at the time of paper jam can be easily performed. Further, by opening the side opening / closing lid on the side surface of the apparatus main body, the belt-shaped intermediate transfer member and the belt-shaped image carrier can be easily attached and detached in accordance with the maintenance process.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. It is widely known that there are one-component and two-component developing systems. The one-component development method has no carrier, so there is no need for developer concentration control or stirring.
It has the advantage that the device is simple and compact. There are two types of this one-component developing method, a magnetic toner type and a non-magnetic toner type. For color use, a non-magnetic toner type having excellent toner color reproducibility is used, but it is used for toner charging, uniform thin layer, etc. However, it is not suitable for a high-speed machine or a device for users who make a large number of copies in a short period of time. The magnetic toner type is used for black and white.

On the other hand, the two-component developing method has a drawback that the apparatus becomes complicated and large, but it is suitable for high-speed, large-volume copying. Therefore, the following examples all use the non-magnetic one-component developing system, and FIG. 1 shows the first example. In the figure, the main constituent elements are a writing unit 30, Y which is a latent image forming means for performing image exposure 3 with a laser beam on a photosensitive belt 1 which is a belt-shaped image carrier.
(Yellow) developing device 101Y, M (magenta) developing device 1
01M, C (cyan) developing device 101C, B (black)
Multi-color developing unit 100 for performing multi-color development by developing device 101B, intermediate transfer belt 20 which is a belt-shaped intermediate transfer member
The intermediate transfer belt unit 200 forms a toner image on the transfer sheet 1 and re-transfers it onto the transfer paper 40, and the fixing unit 300 fixes the toner image. This multicolor developing unit 100 is
Each of the developing devices 101Y, 101M, 101C, 10 is provided in the vicinity of the vertical flat surface of the photoconductor belt 1.
1B has the same component structure and includes the developing sleeves 102Y, 102Y.
02M, 102C, 102B and supply rollers 103Y,
103M, 103C, 103B and developing blade 104
Y, 104M, 104C, 104B and stirring member 105
It has Y, 105M, 105C, and 105B.

The photosensitive belt 1 includes a driving roller 7,
It is supported by the driven roller 8 and the support roller 4,
A static eliminator 6 and a charger 2 are provided in the vicinity of the periphery thereof, and a photosensitive member cleaner 5 as a cleaning unit is integrally provided with the collected toner tank 207 at one end thereof. An OPC system is usually used for the photosensitive belt 1. The intermediate transfer belt unit 2 is provided above the photoconductor belt 1.
00 is arranged, and the intermediate transfer belt 201 which constitutes the intermediate transfer belt unit 200 includes a driving roller 205.
a, the supporting roller 205b, the first bias roller 202a, which is an intermediate transfer means for applying the primary bias voltage,
02b (202 is a primary transfer unit), and an intermediate transfer belt cleaner 206 for cleaning the intermediate transfer belt 201 near the driving roller 205a, and a transfer unit for applying a secondary bias voltage. The second bias roller 204 (203 is a secondary transfer portion) is arranged.

Further, the transfer paper 4 is transferred from the intermediate transfer belt 201.
The drive roller 205, which is a roller at the end portion that supports the intermediate transfer belt 201, has a transfer position for transferring the toner image to 0.
It is provided near a. The material of the intermediate transfer belt 201 is made of polycarbonate, polyester, urethane rubber, unplasticized vinyl chloride, etc., and has a surface resistivity of 1
It is desirable to have a resistance of 0 ⁸ to 10 ⁹ Ω, and seamlessness is advantageous for productivity of printing speed and downsizing of the apparatus. It is essential that the circumference of the belt is longer than the maximum print size. The peripheral length of the photosensitive belt 1 and the peripheral length of the intermediate transfer belt 201 are the same, and the outer diameters of the driving roller 205a and the driving roller 7 are the same, so that the positional deviation occurs. Is being prevented. The transfer paper 40 is stored in the paper feed cassette 41, and a paper feed roller 42 and a registration roller 43 are arranged in order to pull out the transfer paper 40 one by one. In addition, a manual paper feed port 45 for manually feeding paper,
A guide roller 44 is provided. A sheet feeding unit 510 is configured by the sheet feeding cassette 41, the sheet feeding roller 42, the registration roller 43, and the like.

Further, the fixing unit 300 is provided with a fixing roller 301, a pressure roller 302, and a silicone oil coating member 305. The silicone oil coating member 305 enhances the toner fixing property and is used for color printing. A small amount of silicone oil is applied to the fixing roller 301 in order to secure glossiness and color reproducibility. Further, the fixing roller 301 is made of a material such as silicon rubber or fluororubber having high separability with respect to the toner, and has a built-in heater. A paper discharge roller 400 for discharging the fixed transfer paper to the outside of the machine is provided at the rear end of the fixing unit 300. Further, an upper cover 500, which is an upper opening / closing lid, is provided on the upper surface of the apparatus main body, and a lateral cover 501, which is a side opening / closing lid, is provided on the side surface so as to be opened and closed.

By the way, since the static eliminator 6 and the charger 2 are the largest causes of image unevenness due to contamination of corona wires (or rollers), lamps, etc., they are installed at the multicolor developing unit 100 or the photosensitive unit. It is preferable to install it in a position where the toner, the developer, the dust, etc. from the body cleaner 5 are most difficult to reach. In this embodiment, a roller charger is used as the charger 2, but a corona charger may be used. Further, as the photoconductor cleaner 5 and the intermediate transfer belt cleaner 206,
The blade cleaner is the best in terms of cleaning ability, cost, reliability, etc. comprehensively, and in order to enhance the endurance of cleaning ability, the removed substances (cleaned toner, dust such as paper dust, dust etc.) Install in a position where the maximum gravity can be used. The fixing unit 300, the intermediate transfer belt unit 200, the photoconductor unit 530 (see FIG. 2) including the photoconductor belt 1, the photoconductor cleaner 5, and the recovery toner tank 207 are configured to be detachable from the apparatus main body. There is. In the above structure, the original image converted into an electric signal by an image processing / controller (not shown) is written by the writing unit 30 to the photosensitive belt 1
After image exposure (3) on the photosensitive drum 1 to form an electrostatic latent image on the photosensitive belt 1, the electrostatic latent image is formed on the multicolor developing unit 1.
00 to develop. At this time, the toner of each color of yellow, magenta, cyan, and black is stirred by the stirring member 105.
(Y, M, C, B) and supply roller 103 (Y, M, C,
The toner is carried to the developing sleeve 102 (Y, M, C, B) by B), and the toner is thinned by the developing blade 104 (Y, M, C, B), and development is performed. (At the time of non-development, the developing sleeve 102 is separated from the photoconductor belt 1 and cannot be developed by a driving mechanism (not shown). Then, the toner image on the photoconductor belt 1 is formed on the first bias rollers 202a and 202b. By applying a bias voltage to the toner images of respective colors, the toner images of the respective colors are sequentially transferred to the intermediate transfer belt 201 (primary transfer).

On the other hand, the transfer paper 40 in the paper feed cassette 41 is conveyed by a paper feed roller 42 to a registration roller 43, and the registration roller 43 causes the front end of the transfer paper 40 and the toner image on the intermediate transfer belt 201 to coincide with each other. Controlled by. Then, by applying a bias voltage to the second bias roller 204, the toner image on the intermediate transfer belt 201 is transferred to the transfer paper 40 (secondary transfer). The transfer paper 40 after the transfer is sent to the fixing unit 300, and passes between the fixing roller 301 and the pressure roller 302 to fix the toner image. At this time, the fixing property is improved by applying an appropriate amount of silicone oil to the fixing roller 301 by the silicone oil applying member 305.
Then, the paper is ejected to the outside of the machine via the paper ejection roller 400.
Further, the intermediate transfer cleaner 206 is connected to the intermediate transfer belt 201.
The transfer residual toner and dust on the upper part are cleaned, and the removed substances are removed by a transfer member (not shown) from the photoconductor cleaner 5.
Then, the toner is carried to the used recovery toner tank 207. By the way, in the case of carrying out maintenance of the color image forming apparatus of the first embodiment and processing for paper jam, as shown in FIG. 2, by opening and closing the upper cover 500 in the direction of arrow A as necessary. , Open the paper feed path, and fix unit 30
0 is taken out in the direction of arrow B. Further, by opening and closing the lateral cover 501 in the direction of arrow C, the photoconductor unit 530 and the intermediate transfer belt unit 200 are taken out in the direction of arrow D. Further, the paper feeding unit 510 can slide in the arrow E direction.

Next, another embodiment will be described. Figure 3
The second embodiment shown in FIG. 3 has substantially the same configuration as the first embodiment, except that the photosensitive belt 1 is installed horizontally and the intermediate transfer belt 201 is arranged on it. In addition, the multicolor developing unit is different from each developing device 101y, 10y.
The rotary multicolor developing unit 100 ′ in which 1 m, 101 c and 101 b are circularly arranged is used, and this rotary multicolor developing unit 100 ′ is arranged below the photoconductor belt 1. As a fine difference, the peripheral length ratio between the peripheral length of the photosensitive belt 1 and the peripheral length of the intermediate transfer belt 201 is the same peripheral length in the first embodiment, whereas
Integer specific peripheral length (in the second embodiment and the third and fourth embodiments described later, the photosensitive belt 1 and the intermediate transfer belt 20
The circumference ratio of 1 is 1: 2). The maintenance and the process at the time of paper jam of the second embodiment are shown in FIG.
2 is the same as that of the first embodiment shown in FIG. 2, the description thereof will be omitted.

Next, a third embodiment shown in FIG. 5 is similar to the second embodiment described above, except that the photosensitive belt 1 and the intermediate transfer belt 201 on it are slanted. The point is that they are placed at an angle. The maximum print size in this embodiment is A3 size. As shown in FIG. 6, the maintenance and paper jam processing of the third embodiment are similar to those of the first embodiment shown in FIG.

The fourth embodiment shown in FIG. 7 is the same as the second embodiment described above, except that the photosensitive belt 1 is obliquely arranged and the intermediate portion is formed thereon. This is that the transfer belt 201 is arranged horizontally. The maximum print size in this embodiment is A4 size. The maintenance and the processing at the time of paper jam of the fourth embodiment are the same as those of the first embodiment shown in FIG. 2, as shown in FIG.

[0016]

As described above, according to the first aspect, the belt-shaped intermediate transfer member has the transfer means for transferring the toner image onto the transfer paper near one end of the upper flat surface thereof. The belt-shaped image bearing member is provided with a developing device on the vertical flat surface, an intermediate transfer unit for transferring the toner image to the belt-shaped intermediate transfer member on the vertical flat surface, and a lower portion facing the vertical flat surface. Since the static eliminator and the charger are respectively provided on the flat surface, it is possible to achieve compactness, simplification, cost reduction and high reliability of the entire apparatus.

According to Claims 2, 3 and 4, there is provided a rotary multicolor developing unit, and the belt-shaped image carrier comprises:
The belt-shaped intermediate transfer member has an intermediate transfer unit for transferring a toner image to the belt-shaped intermediate transfer member at one end thereof, and a cleaning unit and a discharging / charging unit at the other end thereof. And a cleaning unit disposed near the one end of the upper flat surface of the rotary image forming unit for transferring the toner image onto the transfer paper. Since the belt-shaped image carrier can be made compact, the same effect as in claim 1 can be obtained, and the latent image forming means is attached to the apparatus main body base, so that the polygon mirror can be driven. Vibration due to the motor is also greatly reduced by the highly rigid main body base, which not only hinders the attachment and detachment of the rotary multicolor development unit, etc., but also contributes to the compactness of the main body of the device while improving the image quality. .

According to a fifth aspect of the invention, in addition to the transfer means, a transfer paper conveying means and a fixing means are arranged above the belt-shaped intermediate transfer body, so that the transfer paper is conveyed (feeding paper). The paper can be conveyed horizontally (up to the paper), the conveying distance can be made very short, and the possibility of paper jamming is extremely low, and reliable and high-quality conveyance can be performed. In particular, a separate transport device is not required for transporting the secondary transfer position and the fixing device, which contributes to downsizing of the entire device.

Further, according to the sixth aspect, since the upper opening / closing lid for performing the processing when the paper is jammed is provided on the upper portion of the apparatus main body, the processing when the paper is jammed can be easily performed.

Further, according to the seventh aspect, since the side opening / closing lid is provided on the side surface of the apparatus main body, it is possible to easily perform the maintenance process including the attachment / detachment of the belt-shaped image carrier and the belt-shaped intermediate transfer member. It is effective.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a color image forming apparatus of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing attachment / detachment of each unit of the first embodiment.

FIG. 3 is a schematic configuration diagram showing a color image forming apparatus according to a second embodiment of the present invention.

FIG. 4 is an explanatory view showing the attachment / detachment of each unit of the second embodiment.

FIG. 5 is a schematic configuration diagram showing a color image forming apparatus according to a third embodiment of the present invention.

FIG. 6 is an explanatory view showing the attachment / detachment of each unit of the third embodiment.

FIG. 7 is a schematic configuration diagram showing a color image forming apparatus according to a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram showing the attachment / detachment of each unit of the fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 belt-shaped image carrier 2 charging device 5,206 cleaning means 6 static eliminator 30 latent image forming means 100 multicolor development unit 100 'rotary multicolor development unit 201 belt-shaped intermediate transfer bodies 202a, 202b intermediate transfer means 204 transfer means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location G03G 15/08 7810-2H 15/16 21/00 118

Claims (7)

[Claims] 1. A belt-shaped image carrier, latent image forming means for forming an electrostatic latent image corresponding to an image of each color on the belt-shaped image carrier, and a belt-shaped image carrier arranged around the belt-shaped image carrier. A color including a multicolor developing unit that applies a plurality of colors of developer to the belt-shaped image carrier and one belt-shaped intermediate transfer member that temporarily holds the electrostatic latent image formed on the belt-shaped image carrier. In the image forming apparatus, the belt-shaped intermediate transfer member is supported so as to have at least two flat surfaces including one substantially horizontal flat surface,
A transfer means for transferring the toner image onto the transfer paper is provided near one end of the upper flat surface, and the belt-shaped image carrier has at least two flat surfaces including one vertical flat surface. A multicolor developing unit on the vertical flat surface, an intermediate transfer unit for transferring the toner image to the belt-shaped intermediate transfer member on the vertical flat surface, and a lower surface facing the vertical flat surface. A color image forming apparatus characterized in that a static eliminator and a charger are arranged on a flat surface. 2. In the color image forming apparatus, the multi-color developing unit is a rotary multi-color developing unit which arranges developing devices for respective colors in a circle and performs development while rotating the developing devices, and the belt-shaped image carrier is An intermediate transfer unit for transferring a toner image to the belt-shaped intermediate transfer member is supported at one end of the intermediate transfer unit, which is supported so as to have at least two flat surfaces placed substantially horizontally, and a cleaning unit and a static eliminator at the other end. And a belt-shaped intermediate transfer member, the belt-shaped intermediate transfer member is disposed on an upper portion of the belt-shaped image carrier, and includes at least a lower flat surface arranged so as to contact one end surface of the belt-shaped image carrier. The latent image forming means is supported so as to have two flat surfaces, and has a transfer means and a cleaning means for transferring a toner image onto a transfer paper in the vicinity of one end of the upper flat surface thereof. rotation The color image forming apparatus according to claim 1, characterized in that it is disposed below the multi-color developing unit. 3. The belt-shaped image carrier is obliquely arranged,
The belt-shaped intermediate transfer member is provided on the belt-shaped image carrier,
The color image forming apparatus according to claim 2, wherein the color image forming apparatus is arranged at an inclination smaller than that of the belt-shaped image carrier. 4. The belt-shaped image carrier is obliquely arranged,
The belt-shaped intermediate transfer member is provided on the belt-shaped image carrier,
The color image forming apparatus according to claim 2, wherein the color image forming apparatus is arranged substantially horizontally. 5. A transfer paper transporting means and a fixing means are arranged above the belt-shaped intermediate transfer member in addition to the transfer means. Color image forming apparatus. 6. An upper opening / closing lid for exposing the transfer means and the conveying means to perform processing when a paper jam occurs on an upper portion of the main body of the apparatus.
The described color image forming apparatus. 7. A side opening / closing lid for attaching and detaching a belt-shaped image bearing member and a belt-shaped intermediate transfer member is provided on a side surface of the apparatus main body. Color image forming apparatus.